linux-kernel - Re: [PATCH v5 07/22] liveupdate: luo

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <aRcnRFnqhm3jkqd3@kernel.org>
Date: Fri, 14 Nov 2025 14:57:40 +0200
From: Mike Rapoport <rppt@...nel.org>
To: Pasha Tatashin <pasha.tatashin@...een.com>
Cc: pratyush@...nel.org, jasonmiu@...gle.com, graf@...zon.com,
	dmatlack@...gle.com, rientjes@...gle.com, corbet@....net,
	rdunlap@...radead.org, ilpo.jarvinen@...ux.intel.com,
	kanie@...ux.alibaba.com, ojeda@...nel.org, aliceryhl@...gle.com,
	masahiroy@...nel.org, akpm@...ux-foundation.org, tj@...nel.org,
	yoann.congal@...le.fr, mmaurer@...gle.com, roman.gushchin@...ux.dev,
	chenridong@...wei.com, axboe@...nel.dk, mark.rutland@....com,
	jannh@...gle.com, vincent.guittot@...aro.org, hannes@...xchg.org,
	dan.j.williams@...el.com, david@...hat.com,
	joel.granados@...nel.org, rostedt@...dmis.org,
	anna.schumaker@...cle.com, song@...nel.org, zhangguopeng@...inos.cn,
	linux@...ssschuh.net, linux-kernel@...r.kernel.org,
	linux-doc@...r.kernel.org, linux-mm@...ck.org,
	gregkh@...uxfoundation.org, tglx@...utronix.de, mingo@...hat.com,
	bp@...en8.de, dave.hansen@...ux.intel.com, x86@...nel.org,
	hpa@...or.com, rafael@...nel.org, dakr@...nel.org,
	bartosz.golaszewski@...aro.org, cw00.choi@...sung.com,
	myungjoo.ham@...sung.com, yesanishhere@...il.com,
	Jonathan.Cameron@...wei.com, quic_zijuhu@...cinc.com,
	aleksander.lobakin@...el.com, ira.weiny@...el.com,
	andriy.shevchenko@...ux.intel.com, leon@...nel.org, lukas@...ner.de,
	bhelgaas@...gle.com, wagi@...nel.org, djeffery@...hat.com,
	stuart.w.hayes@...il.com, ptyadav@...zon.de, lennart@...ttering.net,
	brauner@...nel.org, linux-api@...r.kernel.org,
	linux-fsdevel@...r.kernel.org, saeedm@...dia.com,
	ajayachandra@...dia.com, jgg@...dia.com, parav@...dia.com,
	leonro@...dia.com, witu@...dia.com, hughd@...gle.com,
	skhawaja@...gle.com, chrisl@...nel.org
Subject: Re: [PATCH v5 07/22] liveupdate: luo_ioctl: add user interface

On Fri, Nov 07, 2025 at 04:03:05PM -0500, Pasha Tatashin wrote:
> Introduce the user-space interface for the Live Update Orchestrator
> via ioctl commands, enabling external control over the live update
> process and management of preserved resources.
> 
> The idea is that there is going to be a single userspace agent driving
> the live update, therefore, only a single process can ever hold this
> device opened at a time.
> 
> The following ioctl commands are introduced:
> 
> LIVEUPDATE_IOCTL_CREATE_SESSION
> Provides a way for userspace to create a named session for grouping file
> descriptors that need to be preserved. It returns a new file descriptor
> representing the session.
> 
> LIVEUPDATE_IOCTL_RETRIEVE_SESSION
> Allows the userspace agent in the new kernel to reclaim a preserved
> session by its name, receiving a new file descriptor to manage the
> restored resources.
> 
> Signed-off-by: Pasha Tatashin <pasha.tatashin@...een.com>
> ---
>  include/uapi/linux/liveupdate.h  |  64 ++++++++++++
>  kernel/liveupdate/luo_internal.h |  21 ++++
>  kernel/liveupdate/luo_ioctl.c    | 173 +++++++++++++++++++++++++++++++
>  3 files changed, 258 insertions(+)

...
  
> +static int luo_ioctl_create_session(struct luo_ucmd *ucmd)
> +{
> +	struct liveupdate_ioctl_create_session *argp = ucmd->cmd;
> +	struct file *file;
> +	int ret;
> +
> +	argp->fd = get_unused_fd_flags(O_CLOEXEC);
> +	if (argp->fd < 0)
> +		return argp->fd;
> +
> +	ret = luo_session_create(argp->name, &file);
> +	if (ret)

		put_unused_fd(fd) ?

> +		return ret;
> +
> +	ret = luo_ucmd_respond(ucmd, sizeof(*argp));
> +	if (ret) {
> +		fput(file);
> +		put_unused_fd(argp->fd);
> +		return ret;
> +	}

I think that using gotos for error handling is more appropriate here.

> +
> +	fd_install(argp->fd, file);
> +
> +	return 0;
> +}
> +
> +static int luo_ioctl_retrieve_session(struct luo_ucmd *ucmd)
> +{
> +	struct liveupdate_ioctl_retrieve_session *argp = ucmd->cmd;
> +	struct file *file;
> +	int ret;
> +
> +	argp->fd = get_unused_fd_flags(O_CLOEXEC);
> +	if (argp->fd < 0)
> +		return argp->fd;
> +
> +	ret = luo_session_retrieve(argp->name, &file);
> +	if (ret < 0) {
> +		put_unused_fd(argp->fd);
> +
> +		return ret;
> +	}
> +
> +	ret = luo_ucmd_respond(ucmd, sizeof(*argp));
> +	if (ret) {
> +		fput(file);
> +		put_unused_fd(argp->fd);
> +		return ret;
> +	}

and here.

> +
> +	fd_install(argp->fd, file);
> +
> +	return 0;
> +}
> +

-- 
Sincerely yours,
Mike.